Contaminated watermelons cause salmonella outbreak in UK

An outbreak of salmonella bacteria has occurred in the UK, infecting 35 people. The cause has been traced to watermelons.

The BBC has reported that a high number of infections caused from a Salmonella bacterium have been detected across the east of England. In total 35 people have become infected and one person has died as a result of bacterial toxin.

The cases of infection began in December and reached a high-point towards the end of January. Genetic level testing, co-ordinated by the UK Health Protection Agency (HPA), has revealed that the strain causing the infections is the same as a strain detected in Ireland and Germany. The strain of salmonella is called Salmonella newport.

Further testing has linked the bacterial infection to a batch of watermelons. The contamination is likely to have been on the outside of the melons and transferred when the melons were cut. The outside of the melons probably became contaminated from unclean water, which may have been used to wash or to store the fruit.

The HPA notes that Salmonella newport has been found in several different foods in previous UK outbreaks. The worst case was in 2004 and was associated with the lettuce eaten at several restaurants. Salmonella causes diarrhoea, vomiting and fever. In extreme cases it can lead to death.

The Daily Mail reports that the watermelons were imported into Europe from Brazil and then distributed to various countries as involve packs of ready-to-eat sliced watermelon. Brazil is the largest supplier of imported watermelons to the UK shipping around 6,100 tons per year.

The Guardian quotes Bob Adak of the HPA, who states: “"Although it's too soon to say with certainty what the likely cause of infection is, early indications suggest that a number of people became unwell after eating watermelon. This has also been noted in the cases in Scotland and Germany, although further investigation is on-going. It's important to remember that the risk of becoming unwell after eating watermelon is very low. These cases only represent a very small proportion of total consumption. It is always advisable to wash fruits and vegetables – including watermelon – before consumption to reduce the risk of possible illness”.

Last year there were a number of infections of the bacterium E.coi linked to beansprouts which spread across Europe. The 2011 E.coli story was summarised in a special review on the Digital Journal.